Tree felling devices and the like are very well known in the art.
Felling heads are typically mounted at the end of a boom, which itself extends from a tractor, loader or other heavy vehicle. The felling head is usually used to restrain, sever and pile trees prior to further processing.
It is also known in the art to provide a rotation system between the felling head and the outer extremity of the boom in order to enable the felling head to pivot with respect to the tractor. These rotation systems typically comprise a rotational joint and one or more actuators for driving the rotation of the felling head. Also known in the art are the various disadvantages associated with these types of conventional rotation systems.
Known in the art are the following patents and published applications which relate to felling heads and the like: CA 2,115,280, CA 2,146,719, CA 2,165,026, CA 2,165,028, CA 2,186,798, CA 2,188,057, CA 2,242,538, CA 2,242,625, CA 2,291,409, CA 2,305,863, CA 2,546,814, U.S. Pat. No. 4,005,894, U.S. Pat. No. 5,101,872, U.S. Pat. No. 5,408,814, U.S. Pat. No. 5,441,090, U.S. Pat. No. 5,595,225, U.S. Pat. No. 5,727,610, U.S. Pat. No. 5,908,060, U.S. Pat. No. 5,975,177, U.S. Pat. No. 5,975,166, U.S. Pat. No. 6,123,124, U.S. Pat. No. 6,435,235, U.S. Pat. No. 6,516,841 and U.S. Pat. No. 7,296,602.
However, it would be advantageous to provide an improved rotation system with an improved structure and/or operability. There is a need for a device or a system which, by virtue of its design and components, would be able to overcome some of the problems associated with prior art designs.